A self-cleaning heat exchanger (10) has a reversible fan (12) located between two tube banks (14, 16) with a pressure switch (24) connected thereto. The fan (12) rotates in one direction blowing across the first tube bank (14) and drawing air over the second tube bank (16). The pressure switch and fan are interconnected by two relays (28, 30). When the refrigerant pressure in the tube banks exceeds the threshold pressure, the relay (28) is closed and grounded and electric current flows through the relay (30). The change in direction of current flow will reverse the polarity of the windings in motor (13) and thus the rotation of the motor (13) and the fan (12) thereby reversing air flow to remove debris from one tube bank while withdrawing heat from the other without loss of cooling efficiency.